get-func-symbols.el

(let ((syms '()))
  (mapatoms
   (lambda (s)
     (when (fboundp s)
       (push s syms))))
  syms)
;; => (desktop-save-in-desktop-dir gnus-score-mode cl--pass-args-to-cl-declare tabbar-mwheel-switch-tab palette-toggle-verbose eieio-default-eval-maybe haskell-doc-show-reserved ffap-guesser org-babel-pick-name org-move-item-down gnus-put-display-table paredit-enclosing-list-start ...)

;; @see http://lingr.com/room/emacs/archives/2016/01/30#message-22998637
(cl-loop for x being the symbols
  when (fboundp x)
  collect x)